test_ranking.py 文件源码

def check_zero_or_all_relevant_labels(lrap_score):
    random_state = check_random_state(0)

    for n_labels in range(2, 5):
        y_score = random_state.uniform(size=(1, n_labels))
        y_score_ties = np.zeros_like(y_score)

        # No relevant labels
        y_true = np.zeros((1, n_labels))
        assert_equal(lrap_score(y_true, y_score), 1.)
        assert_equal(lrap_score(y_true, y_score_ties), 1.)

        # Only relevant labels
        y_true = np.ones((1, n_labels))
        assert_equal(lrap_score(y_true, y_score), 1.)
        assert_equal(lrap_score(y_true, y_score_ties), 1.)

    # Degenerate case: only one label
    assert_almost_equal(lrap_score([[1], [0], [1], [0]],
                                   [[0.5], [0.5], [0.5], [0.5]]), 1.)